R/C Naval Combat

what is the best, and yet smallest moter, that could be used in small destroyers/cargo vesseles. somewhere i saw a 1/144 pt boat maybe a moto r like that would do

That 1/144th PT Boat had a motor from an medical device. It was pretty spendy.

A good source for micro motors are the little motors used in cell phones and pagers for vibration.

For small destroyers and cargo vessels, you want to use 280-size motors. For cargo boats, you can get gearboxes that slow them down, and you can go direct-drive for high-speed destroyers. The motors used in a PT boat will not be powerful enough to drive a larger ship, due to scaling hydrodynamic forces and the vastly different size between a PT boat and a destroyer.

Just for comparison, the full-size PT boats generated 4,500 HP, whereas fast destroyers generated up to 81,000 HP. Power requirements for model ships are similarly scaled.

Yeah, the guy who built the PT boat had a friend who worked for a company that makes artificial hearts... the motor is actually an artificial heart motor! Pretty cool, huh?

Hmmm... I have occasionally heard the vibration of a ship's engines described as the pulse of the ship. This gives a whole new meaning to that old saying :o

As far as motors go several thoughts occurred to me, for powering the smaller craft. One was the use of zip zaps (made by radio shack) motors, probably limited to use on PT boats. What I’m looking for is something to power either an ice breaker or a costal defense vessel, somewhere between one and two feet long.

If you don't need a ton of speed, an have room for the diameter, the Mabuchi 500TB, aka the Tamiya Solar Motor 02 http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXHA34&P=WR
is very energy efficient (stall draw is less than one A). Now that the drivetrain is broken in, it can push my 22" tramp steamer up to 30-33 knots. These are available from Radio Shack, Frys, etc., and your local hobby store, often cheaper than Tower. This place is a couple of bucks cheaper: http://www.hobbylinc.com/htm/tam/tam76005.htm

I have seen these available surplus for anywhere from about $.50 to $1.50 on the surplus market as raw motors, but the Tamiya kit comes with a nice bracket and the mounting screws.

Cheers,

What about servo motors? Everybody has them and they are plenty small. Anybody ever try to mess with them?

people have turned servos into small forwards/backwards (basically on/off) drive motors. basically, remove the tab from the top of the pot or get rid of it and replace with fixed resistors... regear as necessary.

Found this old thread and couldn't resist answering iceman.

I have made servomotors.

when properly done, they are fully proportional not on-off drives. I have used them in a small 12 inch (not ircwcc) pt boat, and in the smallest convoy used successfully in the IRC - the Japanese T-103 fast transport - their version of the LST. Actually more of an LSM in size and shape. It earned the nickname "the banana boat" and ran off of a std Futaba servo converted to servomotor direct drive. I'll have to go up in the loft and pull it off the shelf to measure it if anyone cares. It was a fun project but very unstable. I would not do it again.

I knew you did and that's why I suggested it. See, I am listening when nobody realizes it...[^]

With care, a motor slightly larger than the one in the servo can be used. The circuit boards heat up if you get crazy ie, draw too much current, but something like a moderate current 180 motor works.

At the last Nats that I ran the little transport probably 6 years ago, I let another caprain drive it, telling him that it must always be patched. Experience showed that 4 holes would sink it. he elected to try to make a second run without patching and it sank. water got in the h2-81 rudder servo and it went max left and stripped its gears. I never fixed it. it was fun to see what I could build when that was the smallest readily available servo.